Stimulating thyrotropin receptor antibodies in early pregnancy.

OBJECTIVES: Thyrotropin-receptor antibodies (TRAb) are used to diagnose Graves' hyperthyroidism in pregnant women. Bioassays provide a measure of thyrotropin-receptor stimulatory antibodies (TSI) specifically. The objective was to measure TSI in pregnant women for establishment of a pregnancy-specific cut-off and comparison with immunoassay measurements of TRAb. METHODS: The retrospective Danish study was performed within the North Denmark Region Pregnancy Cohort (2011-2015) that includes stored biobank samples from early pregnancy (median week 10) with immunoassay measurements of thyroid function parameters and TRAb. TSI were measured in the same samples using the Turbo TSI bioassay (Quidel/Ortho-Clinical Diagnostics) with a recommended cut-off of 0.0241 IU/L in non-pregnant adults. A pregnancy-specific TSI cut-off (95-percentile) was established using Regression on Order Statistics. RESULTS: The established TSI cut-off was 0.0418 IU/L (95 % CI: 0.0417-0.0419). Among women with early pregnancy hyperthyroidism (n=438), 43 women (9.8 %) were TSI positive using the established cut-off, and these women had lower TSH (median 0.008 mIU/L) compared to women with TSI levels below 0.0241 (median TSH 0.040 mIU/L) or in the range from 0.0241 to 0.0418 (median TSH 0.033 mIU/L). Among the 438 women with early pregnancy hyperthyroidism, 22 women were positive for TSI and TRAb, 388 were negative for both, and 28 women were positive for either TSI or TRAb. CONCLUSIONS: This is the first study on TSI measurements in a large cohort of early pregnant women. A pregnancy-specific cut-off for TSI was established and agreement in the classification with immunoassay measurements of TRAb was seen in 94 % of cases.

Endometriosis, polycystic ovary syndrome, and the thyroid: a review.

Endometriosis and polycystic ovary syndrome (PCOS) are common gynecological disorders that constitute a significant burden of disease in women of fertile age. The disorders share a link to female reproduction and infertility; however, divergent effects on menstrual cycle, related hormones, and body composition have been proposed. Disorders of the thyroid gland including abnormal thyroid dysfunction (hyperthyroidism or hypothyroidism) and/or markers of thyroid autoimmunity similarly show a female predominance and onset in younger age groups. We reviewed the literature on the association between endometriosis, PCOS, and thyroid disease up until July 1, 2023, and identified 8 original studies on endometriosis and thyroid disease and 30 original studies on PCOS and thyroid disease. The studies were observational and heterogeneous regarding the design, sample size, and definitions of exposure and outcome; however, a tendency was seen toward an association between hyperthyroidism and endometriosis. Especially an association between endometriosis and slightly elevated levels of thyroid-stimulating hormone receptor antibodies has been found and corroborated in studies from different populations. On the other hand, the literature review turned a focus toward an association between hypothyroidism and PCOS, however, with uncertainties as to whether the association is caused by hypothyroidism per se and/or the thyroid autoantibodies (thyroid peroxidase and thyroglobulin antibodies). More evidence is needed to substantiate an association between endometriosis, PCOS, and thyroid disease, and to differentiate between the role of thyroid function and thyroid autoimmunity. Furthermore, studies are warranted to extend knowledge on the different disease characteristics and underlying mechanisms.

Biochemical markers of renal function and maternal hypothyroidism in early pregnancy.

Objective: The physiological adaptations during a normal pregnancy affect renal and thyroid function and levels of associated biochemical markers. An association between cystatin C (CysC), creatinine, and thyroid function has been considered in nonpregnant individuals but not in pregnant women specifically. Methods: Cohort study within the North Denmark Region Pregnancy Cohort (2011-2015) with assessment of thyroid function and autoantibodies (ADVIA Centaur XPT, Siemens Healthineers) in serum residues from the early pregnancy. Consecutive samples (n = 1112) were selected for measurement of CysC and creatinine (Atellica CH 930, Siemens Healthineers), and results were linked to information in Danish nationwide registers for (i) establishment of pregnancy-specific reference intervals for CysC and creatinine and (ii) evaluation of the prevalence of maternal hypothyroidism in early pregnancy according to levels of CysC and creatinine. Results: The established reference intervals (2.5-97.5 percentiles) differed by week of pregnancy (week 4-8, 9-11, 12-15) and were CysC: 0.58-0.92 mg/L; 0.54-0.91 mg/L; 0.52-0.86 mg/L; creatinine: 46.9-73.0 µmol/L; 42.0-68.4 µmol/L; 38.8-66.4 µmol/L. The prevalence of maternal autoimmune hypothyroidism in early pregnancy differed by the level of CysC and creatinine (<25th percentile; 25th-75th percentile; >75th percentile) and was for CysC 1.7%, 3.8%, 7.4% and for creatinine 2.5%, 4.1%, 7.1%. Conclusions: Reference intervals for CysC and creatinine were dynamic in early pregnancy and decreased with increasing gestational age. Furthermore, higher levels of CysC and creatinine associated with a higher prevalence of maternal autoimmune hypothyroidism. Results encourage considerations on the underlying mechanisms for the association between markers of renal and thyroid function.

Hyperthyroidism in Danish Pregnant Women During a 20-Year Period.

CONTEXT: Hyperthyroidism in pregnancy is a clinical concern, and surveillance of any change in the occurrence of hyperthyroidism in pregnancy is important, especially when a mandatory iodine fortification (IF) program is implemented such as in Denmark in the year 2000. OBJECTIVE: To investigate any change in the occurrence of hyperthyroidism and the use of antithyroid drugs (ATDs) in Danish pregnant women during a 20-year period before and after the implementation of IF. METHODS: A nationwide register-based cohort (1997-2016) and 2 birth cohorts with biochemical data (the Danish National Birth Cohort, 1997-2003, and the North Denmark Region Pregnancy Cohort, 2011-2015) were used to study maternal use of ATDs in pregnancy and frequency of early pregnancy biochemical hyperthyroidism during a 20-year period prior to and after the implementation of mandatory IF. RESULTS: In the nationwide cohort, the adjusted odds ratio (aOR) for treatment with ATDs was 1.51 (95% CI, 1.30-1.74) after mandatory IF (2001-2004) compared with baseline (1997-1999). The increase was more pronounced in the previously moderately iodine-deficient West Denmark (aOR 1.67; 95% CI, 1.36-2.04) than the mildly deficient East Denmark (aOR 1.30; 95% CI, 1.06-1.60) and returned to baseline levels at the end of follow-up in both regions. No time-related difference in early pregnancy biochemical hyperthyroidism was observed. CONCLUSION: The use of ATDs in Danish pregnant women increased following the implementation of IF and then leveled out. Results comply with observations in the general Danish population and suggest that IF influences the occurrence of autoimmune hyperthyroidism in younger individuals.

Cut-offs for thyroid peroxidase and thyroglobulin antibodies in early pregnancy.

Objective: Thyroid disease in women of reproductive age is mainly of autoimmune origin, and thyroid peroxidase antibodies (TPO-Ab) as well as thyroglobulin antibodies (Tg-Ab) are key markers. Adding to this, much focus in pregnancy is on euthyroid women who are thyroid antibody positive. Evidence to substantiate the cut-offs for the definition of thyroid autoantibody positivity in early pregnant women is warranted. Methods: Stored serum samples from 14,030 Danish pregnant women were used for the measurement of TPO-Ab, Tg-Ab, TSH, and free thyroxine (ADVIA Centaur XPT, Siemens Healthineers). Among all women, a reference cohort of 10,905 individuals was identified for the establishment of antibody cut-offs. Percentile cut-offs for TPO-Ab and Tg-Ab were determined using regression on order statistics (the reference cohort). The established cut-offs were then applied (the full cohort), and frequencies of early pregnancy as well as later diagnosis of hypothyroidism were evaluated. Results: The highest established cut-offs (95th, 97.5th, and 99th percentiles) were 59, 68, and 81 U/mL for TPO-Ab and 33, 41, and 52 U/mL for Tg-Ab. When the cut-offs were applied in the full cohort, 11.0, 10.2, and 9.7% were TPO-Ab positive, whereas 13.3, 12.3, and 11.2% were Tg-Ab positive. Antibody-positive women (TPO-Ab and/or Tg-Ab) had higher median TSH and were more likely to have hypothyroidism in early pregnancy and to be diagnosed with hypothyroidism during follow-up. Conclusions: This large study established and evaluated pregnancy-specific cut-offs for TPO-Ab and Tg-Ab. The findings are important regarding the classification of exposure in pregnancy and assessment of thyroid autoimmunity per se.

Thyrotropin Receptor Antibodies in Early Pregnancy.

CONTEXT: Thyrotropin (TSH) receptor antibodies (TRAb) are important when distinguishing between Graves' and gestational hyperthyroidism, but sparse evidence exists on the recommended cutoff during pregnancy. OBJECTIVE: This work aimed to establish a method- and pregnancy-specific cutoff for TRAb, to describe the frequency of TRAb positivity in early pregnancy, and to follow up the women in the years after pregnancy. METHODS: This cohort study used the North Denmark Region Pregnancy Cohort and Danish nationwide registers of women in the North Denmark Region who had a blood sample drawn in early pregnancy, 2011 to 2015, that was stored in a biobank for assessment of thyroid function and thyroid autoantibodies. A cutoff value for TRAb was established in a reference cohort (n = 524) and used to identify TRAb-positive and TRAb-negative hyperthyroidism in early pregnancy for evaluation of frequency and follow-up. RESULTS: The method- and cohort-specific cutoff for TRAb in early pregnancy was 0.98 IU/L (95% CI, 0.96-0.99 IU/L). Among women with low TSH in early pregnancy and no known thyroid disease (n = 414), 21 women (5.1%) were TRAb positive and 393 (94.9%) were TRAb negative. Follow-up in the years following the pregnancy (median 8.1 years) revealed that 52.4% of women with TRAb-positive hyperthyroidism and 8.4% of the women with TRAb-negative hyperthyroidism were diagnosed with hyperthyroidism. CONCLUSION: This is the first study to measure TRAb in a large group of women in early pregnancy and to establish a pregnancy-specific cutoff. Results reveal that TRAb-negative hyperthyroidism is predominant in early pregnancy and rarely associated with later development of hyperthyroidism.

The use of diet interventions to treat symptoms of ADHD in children and adolescents - a systematic review of randomized controlled trials.

Background: For over forty years diet interventions have been investigated as a treatment of ADHD in children and adolescents and, with the new discoveries of the microbiota-gut-brain axis, this research becomes more relevant than ever. The aim of this systematic review was therefore to investigate the current knowledge of diet interventions as a treatment of ADHD in children and adolescentsMethods: A systematic literature search in PubMed was conducted, identifying randomized controlled trials investigating diet interventions to treat ADHD in children and adolescents.Results: The study populations were generally small and the studies varied in duration and nature of the exposure. Overall 10 out of 12 studies spoke in favour of an elimination diet, 2 out of 6 of eliminating artificial food colourings from the diet and none in favour of eliminating sucrose or aspartame from the diet to treat ADHD.Conclusion: The current evidence is not enough to recommend treating ADHD with diet interventions, but a subgroup of children and adolescents might warrant from elimination of certain food-items. Further investigations of the mechanism and effect of diet interventions to treat ADHD is needed.